Kyrie

Kyrie is a supporting character in Devil May Cry 4. Born and raised in Fortuna where she spent most of her days, she is the younger sister of the leader of the Order of the Sword's Holy Knights, Credo, and songstress for the Festival of the Sword. Kyrie is the childhood friend of Nero, as well as his love interest. She carries a necklace that was given to her by Nero at the beginning of the game as a present during the festival. The love between Kyrie and Nero seems to have started before the events of Devil May Cry 4, but their love is used as a major plot point on several occasions during the game.

Description
Kyrie wears a white dress with black boots, similar to what other citizens of Fortuna are seen in. For most of the game she also wears a necklace which Nero gives her at the beginning of the game. It appears to be a golden miniature of a four-winged angel with a red crystal in the center.

Devil May Cry 4
At the beginning of the game she is seen singing Out of Darkness at an Order of the Sword gathering, occasionally glancing at the empty pew where Nero is supposed to be. Nero appears just before the song ends, and he hands her a small gift as she comes to sit beside him while Sanctus explains the history of Sparda's rebellion against Mundus and his demon brethren. As the people begin to pray, Dante crashes in and shoots Sanctus, causing widespread panic which briefly separates Nero from Kyrie. She drops the gift given to her in the confusion, and it is quickly trampled. As Dante approaches her brother Credo, Kyrie is knocked down and cowers in fear before Nero comes to her rescue. Credo orders Nero to hold off the assassin while he takes Kyrie to safety and fetches help. After Nero's skirmish with the Devil Hunter, Kyrie brings him his custom sword. While he prepares it for battle, she locates the contents of her package--a necklace--and puts it on. Afterwards, she goes with Credo as Nero investigates the demon uprising that Dante reportedly caused.

Kyrie is not seen for a long while until she is brought to the duel between her brother and Nero by Agnus. Here, she discovers Nero's Devil Bringer arm that he had been hiding from her. Scared and confused, she does not resist as Agnus captures her and flees the scene. Later on, she is seen as a captive in some kind of magic cage in Agnus's room, where Nero attempts to rescue her. Just when it seems as if Nero has won, as the newly resurrected Sanctus enters the scene, stops him, and takes Kyrie away. Nero strikes out with rage as he tries to break free from the Bianco Angelos that attempt to stall him. He reaches out to grab her, but is only just able to grasp her necklace instead.

Sanctus then takes Kyrie to The Savior, where she is absorbed into its head. This is a ploy by Sanctus to lure Nero into joining her in forming The Savior's core; when Nero refuses, Sanctus and Nero battles. Nero almost wins, but Sanctus makes Kyrie to appear in his place, causing Nero to falter and allowing Sanctus to defeat him.

Kyrie is not seen again until the last mission where she is being kept deep inside of the core of the Savior in a fleshy prison. Nero comes to her rescue and promptly defeats Sanctus Diabolica. The madman threatens to kill her if he advances further, but Nero tosses the Yamato to the false prophet to distract him, then slams him into a wall with the Devil Bringer. With a swift cut from the Yamato, Nero frees Kyrie and impales Sanctus, killing him. Nero escapes the confines of the Savior with Kyrie safe and sound. Sanctus returns as the False Savior, but Nero quickly attends to the matter by pulverizing the twisted visage of the statue while Dante and Kyrie watch. After settling matters with Dante, Nero approaches Kyrie cautiously, unsure of how she will react to his demonic powers. She responds by taking his Devil Bringer in her hands and expresses her desire to be with him, regardless of his nature. The two almost exchange a kiss, but some Scarecrows show up to interrupt the moment. Kyrie patiently waits for Nero as he attends to the matter.

After the post-battle credits, Kyrie and Nero watch some birds fly over the city, with Kyrie taking the Devil Bringer in her hand.

Background
The Kyrie eleison ("Lord have mercy" in Greek) is the first part of the Catholic Ordinary of the Mass. It was traditionally sung in Greek and was translated later in Latin.

Trivia

 * Stephanie Sheh, Kyrie's voice actress, also plays Orihime Inoue in Bleach and Eureka in Eureka Seven. In both, Johnny Yong Bosch, Nero's voice actor, plays her love interests, Ichigo Kurosaki and Renton Thurston. Kyrie's dress is also similar to Orihime's after being captured by the Arrancars.